User guide

Page 83
Genesis II Installation Instructions
© Mass Electronics Pty Ltd 2010Chapter 4 – Commissioning
4-1.2.5 Checking Digital Output Wiring
Digital outputs of the various units are interfaced through relays, each having single-pole changeover
contacts.
The following units contain only Normally Open (NO) digital output contacts in each digital output
channel:
• GENII DDC Digital Controller
• MPCII Mid Points Controller
• GENII DO REM Relay Output Module
• GENII MP REM Multipoint Module
Relay contacts in all units with digital outputs are rated at 24VAC, 2 A with the exception of the MP
REM Multipoint Modules which are rated at 240 AC, 16 A. For this reason, the presence of lethal
voltages at the relay contacts should be anticipated. Even though good wiring practice is to use
lower voltage pilot relays when controlling higher voltage equipment, this practice can not be
guaranteed and it is possible that the relay contacts will carry dangerous voltages. For this reason, it
is important that only a qualified electrician, familiar with safety practices, check the digital output
wiring.
A B
C
D E F
G
H I J
V
AC
V DC
0V
+
-
SWITCH CLOSED
A B
C
D E F
G
H I J
V
AC
V
DC
5V
+
-
SWITCH OPEN
GENII DI REM
GENII DI REM
Figure 4-3: Checking Dry Contact Inputs